5 Jan
2021
5 Jan
'21
8 a.m.
On Tue, Jan 5, 2021, 7:20 AM Paul Koning via cctalk <cctalk at classiccmp.org wrote:
Reading this is true. There are several drivers for this for DOS, linux and
FreeBSD (though the latter may be out of tree). Writing on PC and reading
on a Rainbow is possible, but it is unreliable because the 1.2M drives
aren't that good at writing lower the lower density data rates.
Fun fact: the 720k 3.5" floppies can handle 10 sectors per track just fine.
You can boot a Rainbow off one of these even, but I didn't keep that setup
for reasons I don't recall..
Warner
On Jan 5, 2021, at 6:56 AM, Joshua Rice via
cctalk <
cctalk at classiccmp.org> wrote:
These links may help:
http://decvax.50megs.com/doc/rqdx/rqdx.html <
http://decvax.50megs.com/doc/rqdx/rqdx.html ...
There?s definitely incompatabilities between the RQDX2 and RQDX3. They
shouldn?t
be assumed to be designed or act similarly, despite their names.
The only similarity is that the RQDX3 can read the same floppy disks as the
RQDX2 formats.
It's surprising that the RQDX3 wasn't made format-compatible with the
older controllers.
As for floppies, the RX50 format is the same for all PDP-11/VAX systems.
Unlike hard drives, Pro floppies and RQDX3 floppies are identical. The
geometry is handled in the host for the Pro and in the controller for the
RQDX case, but it's the same geometry. And by the way, a PC floppy drive
can handle RX50 floppies without any trouble, if you set it to the correct
geometry -- in particular, you have to tell it there are 10 sectors per
track rather than the PC default of 9 sectors.